ISTANBUL, Oct 30 (Reuters) - Turkey said it had dismissed a further 10,000 civil servants and closed 15 more media outlets over suspected links with terrorist organisations and U.S.-based cleric Fethullah Gulen, blamed by Ankara for orchestrating a failed coup in July.

More than 100,000 people had already been sacked or suspended and 37,000 arrested since the abortive putsch in an unprecedented crackdown President Tayyip Erdogan says is crucial for wiping out the network of Gulen from the state apparatus.

Thousands more academics, teachers, health workers, prison guards and forensics experts were among the latest to be removed from their posts through two new executive decrees published on the Official Gazette late on Saturday.

Opposition parties described the move as a coup in itself. The continued crackdown has also raised concerns over the functioning of the state.

"What the government and Erdogan are doing right now is a direct coup against the rule of law and democracy," Sezgin Tanrikulu, an MP from the main opposition Republican People's Party (CHP), said in a Periscope broadcast posted on Twitter.

A Turkish court on Sunday formally arrested Gultan Kisanak and Firat Anli, co-mayors of the largely Kurdish southeastern city of Diyarbakir on charges of membership of a terrorist organisation after five days in detention, sources said.

Earlier police used rubber pellets to break up several hundred protesters marching against their arrests. The internet has been largely down in the city for several days, witnesses said.

Turkey's southeast has been rocked by the worst violence in decades since the collapse last year of a ceasefire between the state and the Kurdistan Workers Party (PKK), designated a terrorist organisation by Turkey, the United States and the European Union.

The local prosecutor had said Kisanak, a lawmaker before becoming Diyarbakir's first female mayor in 2014, and Anli had given speeches sympathetic to the PKK, called for greater political autonomy for Turkey's estimated 16 million Kurds and incited violent protests in 2014.

MISUSE

The extent of the crackdown has worried rights groups and many of Turkey's Western allies, who fear Erdogan is using the emergency rule to eradicate dissent. The government says the actions are justified given the threat to the state posed by the coup attempt, in which more than 240 people died.

The executive decrees have ordered the closure of 15 more newspapers, wires and magazines, which report from the largely Kurdish southeast, bringing the total number of media outlets and publishers closed since July to nearly 160.

Universities have also been stripped of their ability to elect their own rectors according to the decrees. Erdogan will from now on directly appoint the rectors from the candidates nominated by the High Educational Board (YOK).

Lale Karabiyik, another CHP lawmaker, said the move was a clear misuse of the emergency rule decrees and described it as a coup d'etat on higher education. Pro-Kurdish opposition said the decrees were used as tools to establish a 'one-man regime'.

The government extended the state of emergency imposed after the coup attempt for three months until mid-January. Erdogan said the authorities needed more time to wipe out the threat posed by Gulen's network as well as Kurdish militants who have waged a 32-year insurgency.

Ankara wants the United States to detain and extradite Gulen so that he can be prosecuted in Turkey on a charge that he masterminded the attempt to overthrow the government. Gulen, who has lived in self-imposed exile in Pennsylvania since 1999, denies any involvement.

Speaking to reporters at a reception marking Republic Day on Saturday, Erdogan said the nation wanted the reinstatement of the death penalty, a debate which has emerged following the coup attempt, and added that delaying it would not be right.

"I believe this issue will come to the parliament," he said, and repeated that he would approve it, a move that would sink Turkey's hopes of European Union membership. Erdogan shrugged off such concerns, saying that much of the world had capital punishment. (Additional reporting by Seyhmus Cakan in Diyarbakir; Editing by Clelia Oziel and Alexandra Hudson)